At 9 a.m., Bryan started from City U and travelled towards City V and his speed remained constant throughout. At 10 a.m., Yen started her journey from City U towards City V at an average speed of 68 km/h. Yen overtook Bryan at 1 p.m. After overtaking, Yen carried on her journey at the same average speed and reached at City V at 4:45 p.m.

1. Find Bryan's average speed in km/h.
2. What is the distance between the two cities?

(a)
From 10 a.m. to 1 p.m. = 3 h

Distance that Yen had travelled until Yen overtook Bryan
= 3 x 68
= 204 km

From 9 a.m. to 1 p.m. = 4 h

Bryan's average speed
= 204 ÷ 4
= 51 km/h

(b)
From 10 a.m. to 4:45 p.m. = 6 h 45 min

1 h = 60 min
6 h 45 min = 6 ⁴⁵ ₆₀
 h = 6 ³₄ h

Distance between the two cities
= 6 ³₄ x 68
= ²⁷₄ x 68
= 459 km

Answer(s): (a) 51 km/h; (b) 459 km